1. Field of the Invention:
This invention relates to lock mechanisms, and particularly a door lock mechanism equipped with an anti-pick device.
2. Background Discussion:
A deadlocking latch is described in U.S. Pat. No. 3,073,143 which provides a lock mechanism wherein a spring actuated bolt is deadlocked in a locked position and manually unlocked using a key control member. This deadlocking latch has been a widely accepted lock mechanism and has been used in a variety of applications. One disadvantage of this lock mechanism is that it may be picked by inserting a shim between the bolt and an opening in the lock casing to disengage the bolt by forcing a pin that projects laterally into the casing side.